I can understand a distributor of alcoholic beverages not permitting firearms on their property. Look at the violent history of the alcohol industry during the Prohibition era and all the mob activity generated around alcohol during that time. If it was a mom& pop store, I could see your situation about boycot of the establishment, but distribution center with interstate commerce has other concerns. Also, the business is a private person, and has the right to limit possession of firearms on the property.
I don't carry a gun to kill someone. I carry a gun to avoid being a victim! Gary